Surveys show that it is as difficult if not more difficult for pregnant women to give up cigarettes than for them to give up cocaine or heroin. Cigarette smoking during pregnancy is the cause of increased premature births, birth defects, diminished birth weight, and fetal mortality. The fact that the fetus is exposed to similar levels of nicotine, including cigarette smoke produced nicotine boli via the umbilical artery, suggests that nicotine tolerance and physical dependence may develop in the uterus. Animal research has shown that neonatal nicotine exposure induces the increased numbers of nicotinic receptors confirming that such exposure can induce morphological changes. The possibility that a neonatal nicotine withdrawal syndrome may occur due to the abrupt termination of nicotine exposure to the fetus upon birth has not been explored. Whether or not a neonatal nicotine withdrawal syndrome occurs (it may not be due to the possibility that the neonate detoxifies nicotine very slowly) is important from both a theoretical as well as public health perspective. If a neonatal nicotine withdrawal syndrome does occur this could have a negative impact on purely mother-infant interactions since the newborn might be a more "difficult" baby. Documenting such withdrawal syndrome is challenging because of the constraints of assessment on a neonatal unit. There, measures include structured observation forms completed by attending nurses, Brazleton neonatal evaluation procedure, and structured infant cry recordings (including both spontaneous, evoked, and PKU test associated with cry samples. Cryographic analysis will be conducted by Dr. Barry Lester who has developed procedures used to assess various physiological abnormalities to document the adverse impact of states such as malnutrition, alcohol and opioid withdrawal.